This means that we can honor -fdata-sections rather than
always creating a segment for each symbol.
It also allows for a followup change to add .init_array and friends.
Differential Revision: https://reviews.llvm.org/D37876
llvm-svn: 313395
Looks like these were copied from the ELF sections but
don't apply to Wasm and were not used anywhere.
Also remove unused Wasm methods in MCContext.
Differential Revision: https://reviews.llvm.org/D37633
llvm-svn: 313058
I was surprised to see the code model being passed to MC. After all,
it assembles code, it doesn't create it.
The one place it is used is in the expansion of .cfi directives to
handle .eh_frame being more that 2gb away from the code.
As far as I can tell, gnu assembler doesn't even have an option to
enable this. Compiling a c file with gcc -mcmodel=large produces a
regular looking .eh_frame. This is probably because in practice linker
parse and recreate .eh_frames.
In llvm this is used because the JIT can place the code and .eh_frame
very far apart. Ideally we would fix the jit and delete this
option. This is hard.
Apart from confusion another problem with the current interface is
that most callers pass CodeModel::Default, which is bad since MC has
no way to map it to the target default if it actually needed to.
This patch then replaces the argument with a boolean with a default
value. The vast majority of users don't ever need to look at it. In
fact, only CodeGen and llvm-mc use it and llvm-mc just to enable more
testing.
llvm-svn: 309884
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.
Differential Revision: https://reviews.llvm.org/D33843
llvm-svn: 304864
. there should be no runtime relocation inside the bpf function.
. relocation supported here mostly for debugging.
. a test case is added.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
llvm-svn: 302055
All MIPS .debug_* sections should be marked with ELF type SHT_MIPS_DWARF
accordingly the specification [1]. Also the same section type is assigned
to these sections by GNU tools.
[1] ftp.software.ibm.com/software/os390/czos/dwarf/mips_extensions.pdf
Differential Revision: https://reviews.llvm.org/D29789
llvm-svn: 297447
With the "wasm32-unknown-unknown-wasm" triple, this allows writing out
simple wasm object files, and is another step in a larger series toward
migrating from ELF to general wasm object support. Note that this code
and the binary format itself is still experimental.
llvm-svn: 296190
This just adds the basic skeleton for supporting a new object file format.
All of the actual encoding will be implemented in followup patches.
Differential Revision: https://reviews.llvm.org/D26722
llvm-svn: 295803
On ELF every section can have a corresponding section symbol. When in
an assembly file we have
.quad .text
the '.text' refers to that symbol.
The way we used to handle them is to leave .text an undefined symbol
until the very end when the object writer would map them to the
actual section symbol.
The problem with that is that anything before the end would see an
undefined symbol. This could result in bad diagnostics
(test/MC/AArch64/label-arithmetic-diags-elf.s), or incorrect results
when using the asm streamer (est/MC/Mips/expansion-jal-sym-pic.s).
Fixing this will also allow using the section symbol earlier for
setting sh_link of SHF_METADATA sections.
This patch includes a few hacks to avoid changing our behaviour when
handling conflicts between section symbols and other symbols. I
reported pr31850 to track that.
llvm-svn: 293936
The main issue here is that the "thumb" flag wasn't set for some of these
sections, making MSVC's link.exe fails to correctly relocate code
against the symbols inside these sections. link.exe could fail for
instance with the "fixup is not aligned for target 'XX'" error. If
linking doesn't fail, the relocation process goes wrong in the end and
invalid code is generated by the linker.
This patch adds Thumb/ARM information so that the right flags are set
on COFF/Windows.
Patch by Adrien Guinet.
llvm-svn: 273880
MC only needs to know if the output is PIC or not. It never has to
decide about creating GOTs and PLTs for example. The only thing that
MC itself uses this information for is expanding "macros" in sparc and
mips. The rest I am pretty sure could be moved to CodeGen.
This is a cleanup and isolates the code from future changes to
Reloc::Model.
llvm-svn: 269909
Changed emitting offset of macinfo entry into compiler unit DIE to use "addSectionLabel" method rather than explicitly calculating size/offset of macro entry.
Differential Revision: http://reviews.llvm.org/D16292
llvm-svn: 259358
Summary:
There are three parts to inlined call frames:
1. The inlinee line subsection
2. The inline site symbol record
3. The function ids referenced by both
This change starts by emitting function ids (3) for all subprograms and
emitting the base inline site symbol record (2). The actual line numbers
in (2) use an encoded format that will come next, along with the inlinee
line subsection.
Reviewers: majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D16333
llvm-svn: 259217
Various bits we want to use the new ABI actually compile with "-arch armv7k
-miphoneos-version-min=9.0". Not ideal, but also not ridiculous given how
slices work.
llvm-svn: 258975
InitMCObjectFileInfo was trying to override the triple in awkward ways.
For example, a triple specifying COFF but not Windows was forced as ELF.
This makes it easy for internal invariants to get violated, such as
those which triggered PR25912.
This fixes PR25912.
llvm-svn: 256226
This is very rudimentary support for debug_cu_index, but it is enough to
allow llvm-dwarfdump to find the offsets for contributions and
correctly dump debug_info.
It will need to actually find the real signature of the unit and build
the real hash table with the right number of buckets, as per the DWP
specification.
It will also need to be expanded to cover the tu_index as well.
llvm-svn: 254489
If a section is rw, it is irrelevant if the dynamic linker will write to
it or not.
It looks like llvm implemented this because gcc was doing it. It looks
like gcc implemented this in the hope that it would put all the
relocated items close together and speed up the dynamic linker.
There are two problem with this:
* It doesn't work. Both bfd and gold will map .data.rel to .data and
concatenate the input sections in the order they are seen.
* If we want a feature like that, it can be implemented directly in the
linker since it knowns where the dynamic relocations are.
llvm-svn: 253436
The way prelink used to work was
* The compiler decides if a given section only has relocations that
are know to point to the same DSO. If so, it names it
.data.rel.ro.local<something>.
* The static linker puts all of these together.
* The prelinker program assigns addresses to each library and resolves
the local relocations.
There are many problems with this:
* It is incompatible with address space randomization.
* The information passed by the compiler is redundant. The linker
knows if a given relocation is in the same DSO or not. If could sort
by that if so desired.
* There are newer ways of speeding up DSO (gnu hash for example).
* Even if we want to implement this again in the compiler, the previous
implementation is pretty broken. It talks about relocations that are
"resolved by the static linker". If they are resolved, there are none
left for the prelinker. What one needs to track is if an expression
will require only dynamic relocations that point to the same DSO.
At this point it looks like the prelinker is an historical curiosity.
For example, fedora has retired it because it failed to build for two
releases
(http://pkgs.fedoraproject.org/cgit/prelink.git/commit/?id=eb43100a8331d91c801ee3dcdb0a0bb9babfdc1f)
This patch removes support for it. That is, it stops printing the
".local" sections.
llvm-svn: 253280
We now create the .eh_frame section early, just like every other special
section.
This means that the special flags are visible in code that explicitly
asks for ".eh_frame".
llvm-svn: 252313
Recommit r250342: move coal-sections-powerpc.s to subdirectory for powerpc.
Some background on why we don't have to use *coal* sections anymore:
Long ago when C++ was new and "weak" had not been standardized, an attempt was
made in cctools to support C++ inlines that can be coalesced by putting them
into their own section (TEXT/textcoal_nt instead of TEXT/text).
The current macho linker supports the weak-def bit on any symbol to allow it to
be coalesced, but the compiler still puts weak-def functions/data into alternate
section names, which the linker must map back to the base section name.
This patch makes changes that are necessary to prevent the compiler from using
the "coal" sections and have it use the non-coal sections instead when the
target architecture is not powerpc:
TEXT/textcoal_nt instead use TEXT/text
TEXT/const_coal instead use TEXT/const
DATA/datacoal_nt instead use DATA/data
If the target is powerpc, we continue to use the *coal* sections since anyone
targeting powerpc is probably using an old linker that doesn't have support for
the weak-def bits.
Also, have the assembler issue a warning if it encounters a *coal* section in
the assembly file and inform the users to use the non-coal sections instead.
rdar://problem/14265330
Differential Revision: http://reviews.llvm.org/D13188
llvm-svn: 250370
Recommit r250342: add -arch=ppc32 to the RUN lines of powerpc tests.
Some background on why we don't have to use *coal* sections anymore:
Long ago when C++ was new and "weak" had not been standardized, an attempt was
made in cctools to support C++ inlines that can be coalesced by putting them
into their own section (TEXT/textcoal_nt instead of TEXT/text).
The current macho linker supports the weak-def bit on any symbol to allow it to
be coalesced, but the compiler still puts weak-def functions/data into alternate
section names, which the linker must map back to the base section name.
This patch makes changes that are necessary to prevent the compiler from using
the "coal" sections and have it use the non-coal sections instead when the
target architecture is not powerpc:
TEXT/textcoal_nt instead use TEXT/text
TEXT/const_coal instead use TEXT/const
DATA/datacoal_nt instead use DATA/data
If the target is powerpc, we continue to use the *coal* sections since anyone
targeting powerpc is probably using an old linker that doesn't have support for
the weak-def bits.
Also, have the assembler issue a warning if it encounters a *coal* section in
the assembly file and inform the users to use the non-coal sections instead.
rdar://problem/14265330
Differential Revision: http://reviews.llvm.org/D13188
llvm-svn: 250349
Some background on why we don't have to use *coal* sections anymore:
Long ago when C++ was new and "weak" had not been standardized, an attempt was
made in cctools to support C++ inlines that can be coalesced by putting them
into their own section (TEXT/textcoal_nt instead of TEXT/text).
The current macho linker supports the weak-def bit on any symbol to allow it to
be coalesced, but the compiler still puts weak-def functions/data into alternate
section names, which the linker must map back to the base section name.
This patch makes changes that are necessary to prevent the compiler from using
the "coal" sections and have it use the non-coal sections instead when the
target architecture is not powerpc:
TEXT/textcoal_nt instead use TEXT/text
TEXT/const_coal instead use TEXT/const
DATA/datacoal_nt instead use DATA/data
If the target is powerpc, we continue to use the *coal* sections since anyone
targeting powerpc is probably using an old linker that doesn't have support for
the weak-def bits.
Also, have the assembler issue a warning if it encounters a *coal* section in
the assembly file and inform the users to use the non-coal sections instead.
rdar://problem/14265330
Differential Revision: http://reviews.llvm.org/D13188
llvm-svn: 250342
This prevents MC clients from getting COFF.h, which conflicts with
winnt.h macros. Also a minor IWYU cleanup. Now the only public headers
including COFF.h are in Object, and they actually need it.
llvm-svn: 246784
This reverts commit r245047.
It was failing on the darwin bots. The problem was that when running
./bin/llc -march=msp430
llc gets to
if (TheTriple.getTriple().empty())
TheTriple.setTriple(sys::getDefaultTargetTriple());
Which means that we go with an arch of msp430 but a triple of
x86_64-apple-darwin14.4.0 which fails badly.
That code has to be updated to select a triple based on the value of
march, but that is not a trivial fix.
llvm-svn: 245062
Other than some places that were handling unknown as ELF, this should
have no change. The test updates are because we were detecting
arm-coff or x86_64-win64-coff as ELF targets before.
It is not clear if the enum should live on the Triple. At least now it lives
in a single location and should be easier to move somewhere else.
llvm-svn: 245047
Sam Clegg